The question I was going to ask. How hard are you pushing them. And I would use a taper crimp, although some folks successfully roll crimp them.
I had a revolver that would not shoot plated bullets no matter what crimp or velocity, my guess was poorly aligned chambers, dunno. It shot jacketed great. Might not be the bullet, might be too much crimp, might be a combination of things.
I shoot a couple of different X-Treme bullets and like them, but they don't like to be abused much. The Powerbond is a better choice to try to push real hard. I shoot a 200 Gr X-Treme (Among other things), in .44 Spl with a taper crimp and they perform well.
Bottom line, yes, I would say that crimp is pushing the envelope, especially if you are trying to run full loads.